Plug coming loose?

[IGASAURUS]

I recently upgraded my YZ to a 144. The Athena kit came with several base gaskets, but I only put one of them on. Since then it's ran perfect except for the plug backing itself out. So much so that after every ride I could finger tighten it.

Only had a few rides of this happening and want to fix the problem before I have another rebuild on my hands. How much of a difference can gasket thickness (or number of gaskets) really make? I'm no mechanic, but I know this isn't normal.

P.S. I counting on you Falcon :lol:

[Aus_Rider_22]

I think the gasket options are for changing the squish band which affects compression. Adding more gaskets will push the head and plug a bee's dick further from the top of the piston stroke. From memory you are moving the power slightly higher in the range and dropping the compression a touch.

I would think no matter than gasket setup, your plug shouldn't be making its way loose. You using a torque wrench Tim?

[IGASAURUS]

For the plug? No. Just a normal plug wrench like I always have without any problems.

[Crash11]

A lot of stuff can probably be tightened by feel, but this isn't one of those. Any time you are putting steel threads into an aluminum block, you should torque it to spec. I'd put anti-seize on it too.

Check the head manufacturer for a torque spec. Should be in the area of 15 ft-lbs.

[Falcon991]

Your bigger bore is probably causing more vibration, also.

BTW, the rule of thumb for spark plugs when the compression washer is new is "finger tight, plus one quarter turn." (Which is probably exactly 15 lb./feet.)

[Erick]

the cause of the plug coming out is the frequency of the vibration caused by every rotating and translating part. This makes the plug vibrate in its 'natural frequency'. What you need to do is to give the sparkplug some form of 'damping'. I would use a litte bit of loctide when you tighten the plug, this could help but it can also rattle loose if the vibrations are to strong. Then I would opt to use some form of pipe sealant which is used to seal the thread of pipe connectors. Maybe you can ask you local plumbing company and ask them for a solution?

If any of those doesn't work you can always weld the spark plug to the cilinder :rotfl: